When you’re throwing, it is important to focus on a small, specific target.
Byron Putman describes it this way in his book Petanque (p. 64).
Great au fer shooters have “the eyes”… for several seconds they lock their gaze laser-like on the target boule as if it were the only object in the universe…. For some shooters locking their vision on the target boule is not enough. They create a more precise bull’s-eye by staring at a single point on the target.
This is called target focus. It is as important for accurate pointing as it is for accurate shooting. Focussing on a small and very specific spot for your donnée is important. That’s why, in the “mental” part of our page on How to throw a boule, we emphasize picking the donnée and paying attention to where the thrown boule lands.
Your mantra here is
Aim small; miss small.
Here’s a good explanation of how to do it.